TWI827636B - Solid-state imaging element, solid-state imaging device, and manufacturing method of solid-state imaging element - Google Patents

Abstract

The present invention provides a solid-state imaging element (100), which is provided with: a semiconductor substrate (500); a charge accumulation part that is provided in the semiconductor substrate (500) and accumulates charges; and a photoelectric conversion part (200) that is provided in the aforementioned semiconductor substrate (500). above the semiconductor substrate (500), and converts light into charges; and a through-electrode (600), which penetrates the semiconductor substrate (500) and electrically connects the charge accumulation part and the photoelectric conversion part (200); and The end portion of the through-electrode (600) on the side of the photoelectric conversion portion is along the cross-sectional area of the conductor (602) located in the center of the through-electrode (600) and perpendicular to the penetration direction of the through-electrode (600). The penetration direction gradually increases toward the photoelectric conversion portion.

Description

Solid-state imaging element, solid-state imaging device, and manufacturing method of solid-state imaging element

The present invention relates to a solid-state imaging element, a solid-state imaging device and a manufacturing method of the solid-state imaging element.

In recent years, the industry has discussed solid-state imaging elements such as CCD (Charge Coupled Device) image sensors or CMOS (Complementary Metal-Oxide-Semiconductor) image sensors. , a through-electrode is provided for each pixel (solid-state imaging element). For example, an example of such a solid-state imaging element is a solid-state imaging element disclosed in Patent Document 1 below. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2017-073436

[Problem to be solved by the invention]

However, in the through-electrode disclosed in the above-mentioned Patent Document 1, it is difficult to suppress the resistance value of the through-electrode to be low.

Therefore, in view of this situation, the present invention proposes a novel and improved solid-state imaging element, a solid-state imaging device, and a manufacturing method of a solid-state imaging element that can suppress the resistance value of the through-electrode to a low value. [Technical means to solve problems]

According to the present invention, there is provided a solid-state imaging element, which is provided with: a semiconductor substrate; a charge storage unit that is provided in the semiconductor substrate and accumulates charges; and a photoelectric conversion unit that is provided above the semiconductor substrate and converts light converted into electric charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and the end of the through-electrode on the side of the photoelectric conversion part is located in the center of the through-electrode The cross-sectional area of the cross section of the conductor perpendicular to the penetration direction of the through-electrode gradually increases toward the photoelectric conversion portion along the penetration direction.

Furthermore, according to the present invention, there is provided a solid-state imaging device including a plurality of solid-state imaging elements arranged in a matrix, and each of the solid-state imaging elements includes: a semiconductor substrate; and a charge accumulation portion provided in the semiconductor substrate, and Accumulating electric charges; a photoelectric conversion part that is disposed above the semiconductor substrate and converts light into electric charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge accumulation part and the photoelectric conversion part; and in the above-mentioned The cross-sectional area of the end of the through-electrode on the side of the photoelectric conversion portion and the conductor located at the center of the through-electrode is orthogonal to the penetration direction of the through-electrode, and gradually increases toward the photoelectric conversion portion in the penetration direction.

Furthermore, according to the present invention, there is provided a method of manufacturing a solid-state imaging element, which is provided with: a semiconductor substrate; a charge accumulation portion provided in the semiconductor substrate and which accumulates charges; and a photoelectric conversion portion provided in the semiconductor substrate. above, and converts light into charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and the end of the through-electrode on the side of the photoelectric conversion part is located The cross-sectional area of the conductor at the center of the through-electrode that is perpendicular to the penetration direction of the through-electrode gradually increases toward the photoelectric conversion portion along the penetration direction; and the manufacturing method includes: Forming a through hole penetrating the semiconductor substrate; forming an insulating film to cover the inner wall of the through hole; etching the insulating film at an end portion of the through hole on the side of the photoelectric conversion portion; and burying it with a metal film Enter the aforementioned through hole. [Effects of the invention]

As explained above, according to the present invention, the resistance value of the through-electrode can be suppressed to be low.

In addition, the above-mentioned effects are not necessarily limiting effects. The present invention can exert the above-mentioned effects, and/or can exert any of the effects shown in this specification, or other effects that can be understood based on this specification, in place of the above-mentioned effects.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in this specification and the drawings, components having substantially the same functional configuration are assigned the same reference numerals, and repeated descriptions will be omitted.

Furthermore, in this specification and the drawings, similar components in different embodiments may be distinguished by assigning different letters after the same symbol. However, when there is no need to specifically distinguish between similar constituent elements, only the same symbol is given.

In addition, the drawings referred to in the following description are used to facilitate the description and understanding of the embodiments of the present invention. For the convenience of understanding, the shapes, dimensions, ratios, etc. shown in the drawings may be different from the actual ones. . Furthermore, the solid-state imaging element and the solid-state imaging device shown in the figures can be appropriately designed with reference to the following description and well-known technologies. In addition, the up-down direction of the stacked structure of the solid-state imaging element in the explanation using the cross-sectional view of the solid-state imaging element corresponds to the relative direction when the incident surface of the light incident on the solid-state imaging element is upward, and the up-down direction according to the actual gravitational acceleration Different directions.

In addition, the description of specific sizes and shapes in the following description does not only mean the same values as mathematically defined values or geometrically defined shapes, but also includes industrial differences in the manufacturing process of solid-state imaging elements. Allowable degree of difference, etc. and shapes similar to this shape. For example, when it is expressed as "cylindrical" or "substantially cylindrical" in the following description, it is not limited to a cylinder whose upper surface and lower surface are perfect circles, but also means a shape similar to a perfect circle such as an ellipse. Shape the upper and lower surfaces of a cylinder.

Furthermore, in the following description of the circuit structure, unless there is any special objection, the so-called "electrical connection" means connecting multiple elements in an electrically conductive manner. In addition, "electrical connection" in the following description is assumed to include not only the case of directly and electrically connecting multiple elements, but also the case of indirect and electrical connection through other elements.

In addition, in the following description, the so-called "gate" refers to the gate electrode of a field effect transistor (FET). The so-called "drain" refers to the drain electrode or drain region of the FET, and the so-called "source" refers to the source electrode or source region of the FET.

In addition, the explanation is carried out in the following order. 1. About the general structure of the solid-state imaging device 1 2. About the equivalent circuit of the solid-state imaging element 100 3. Regarding the multilayer structure of the solid-state imaging element 100 4. The process of forming the embodiment of the present invention 5. First embodiment 5.1 Detailed structure of through-electrode 600 5.2 About the manufacturing method of the solid-state imaging element 100 5.3 Variation examples 6. Second embodiment 7. Third embodiment 8. Fourth embodiment 9. Fifth embodiment 10. Summary 11. Application examples of endoscopic surgery system 12. Application examples for moving objects 13.Supplementary

＜＜1. About the general structure of the solid-state imaging device 1 >> First, before describing each embodiment of the present invention, the schematic structure of the solid-state imaging device 1 according to each embodiment of the present invention will be described with reference to FIG. 1 . FIG. 1 is a schematic plan view of the solid-state imaging device 1 of this embodiment. As shown in FIG. 1 , the solid-state imaging device 1 of this embodiment includes a pixel array unit 10 in which a plurality of solid-state imaging elements (pixels) 100 are arranged in a matrix on a semiconductor substrate 500 made of, for example, silicon. Furthermore, as shown in FIG. 1 , the solid-state imaging device 1 includes a vertical drive circuit unit 32, a horizontal signal processing circuit unit 34, a horizontal drive circuit unit 36, an output circuit unit 38, a control circuit unit 40, and the like. The details of each block of the solid-state imaging device 1 of this embodiment will be described below.

(Pixel array section 10) The pixel array unit 10 has a plurality of solid-state imaging elements 100 two-dimensionally arranged in a matrix (column-like) shape on a semiconductor substrate 500 . In addition, here, the solid-state imaging element 100 refers to a solid-state imaging element (unit pixel) that can be understood as one unit (unit pixel) that outputs one result for each color when it detects light of each color and outputs a detection result. Each solid-state imaging element 100 has a plurality of photoelectric conversion elements (Photo Diodes; PDs) (photoelectric conversion portions) capable of generating charges corresponding to the amount of incident light of each color (for example, the solid-state imaging element 100 is shown in the figure) 4 may include three stacked PDs 200, 300, and 400) and a plurality of pixel transistors (such as MOS (Metal-Oxide-Semiconductor, metal oxide semiconductor) transistors) (not shown). In more detail, the pixel transistor may include, for example, a transfer transistor, a selection transistor, a reset transistor, an amplification transistor, etc.

In addition, the above-mentioned solid-state imaging element 100 may also have a shared pixel structure. This shared pixel structure is composed of a plurality of the above-mentioned PDs, a plurality of the above-mentioned transfer transistors, one floating diffusion part (floating diffusion region) (charge storage part) shared among the above-mentioned PDs and accumulating charges generated in the PD, and the above-mentioned Each PD is composed of one other pixel transistor shared between PDs. That is, it can be said that in each of the above-mentioned shared pixel structures, a plurality of photoelectric conversion pairs composed of PDs and transfer transistors are provided, and each of the photoelectric conversion pairs shares other pixel transistors (selection transistors, reset transistors, and amplification transistors). transistors, etc.). In addition, details of the circuit (connection structure) composed of these pixel transistors will be described later.

(Vertical drive circuit section 32) The vertical drive circuit section 32 is formed of, for example, a shift register, selects a pixel drive wiring 42, supplies a pulse for driving the solid-state imaging element 100 to the selected pixel drive wiring 42, and drives the solid-state imaging element 100 in column units. That is, the vertical drive circuit section 32 sequentially selects and scans each solid-state imaging element 100 of the pixel array section 10 in the vertical direction (up and down direction in FIG. 1 ) in column units, and controls the row signal processing circuit section to be described later via the vertical signal line 44 34 supplies a pixel signal based on an electric charge generated according to the amount of light received by the PD of each solid-state imaging element 100 .

(Line signal processing circuit section 34) The row signal processing circuit unit 34 is arranged for each row of the solid-state imaging elements 100 and performs signal processing such as noise removal on the pixel signals output from the solid-state imaging elements 100 for one column for each pixel row. For example, the row signal processing circuit unit 34 performs signal processing such as CDS (Correlated Double Sampling) and AD (Analog-Degital) conversion in order to remove fixed pattern noise inherent to the pixels.

(Horizontal drive circuit section 36) The horizontal drive circuit section 36 is formed of, for example, a shift register. By sequentially outputting horizontal scan pulses, the horizontal drive circuit sections 34 can be sequentially selected to drive the pixel signals from each of the signal processing circuit sections 34 to the horizontal direction. The signal line 46 outputs.

(Output circuit section 38) The output circuit unit 38 can perform signal processing on and output the pixel signals supplied sequentially from each of the above-mentioned row signal processing circuit units 34 via the horizontal signal line 46 . The output circuit unit 38 may function as a functional unit that performs buffering, for example, or may perform processing such as black level adjustment, line offset correction, and various digital signal processing. In addition, buffering refers to temporarily storing pixel signals in order to compensate for the difference between processing speed and transmission speed when pixel signals are exchanged. In addition, the input/output terminal 48 is a terminal used for exchanging signals with an external device.

(Control circuit unit 40) The control circuit unit 40 can receive data such as an input clock, a commanded operation mode, and the like, and can output data such as internal information of the solid-state imaging element 100 . That is, the control circuit unit 40 generates a clock signal that serves as a reference for the operations of the vertical drive circuit unit 32, the horizontal signal processing circuit unit 34, the horizontal drive circuit unit 36, etc., based on the vertical synchronization signal, the horizontal synchronization signal and the main clock. control signal. Furthermore, the control circuit unit 40 outputs the generated clock signal and control signal to the vertical drive circuit unit 32, the horizontal drive circuit unit 34, the horizontal drive circuit unit 36, and the like.

As described above, the above-mentioned solid-state imaging device 1 is a so-called line AD type CMOS image sensor in which the line signal processing circuit unit 34 that performs CDS processing and AD conversion processing is arranged for each pixel line. In addition, the planar structure example of the solid-state imaging device 1 of this embodiment is not limited to the example shown in FIG. 1 , and may include other circuit parts, etc., without particular limitation.

＜＜2. About the equivalent circuit of the solid-state imaging element 100 >> The schematic configuration of the solid-state imaging device 1 according to this embodiment has been described above. Next, equivalent circuits of the PDs 200, 300, and 400 included in the solid-state imaging element 100 according to the embodiment of the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is an equivalent circuit diagram of the PD 200 included in the solid-state imaging device 100 of this embodiment, and FIG. 3 is an equivalent circuit diagram of the PD 300 included in the solid-state imaging device 100 of this embodiment.

The details of the stacked structure of the PD 200 will be described later. As shown schematically in the upper left corner of FIG. 2 , the PD 200 has an upper electrode (common electrode) 202 and a lower electrode (readout electrode) 206 stacked on a silicon substrate, that is, a semiconductor substrate 500 . , and a laminated structure of the photoelectric conversion film 204 sandwiched between the upper electrode 202 and the lower electrode 206 .

As shown in FIG. 2 , the upper electrode 202 is electrically connected to the selection line V _OU for selecting the row to output the pixel signal. Specifically, the lower electrode 206 is electrically connected to one of the drain and the source of the reset transistor TR1 _rst for resetting the accumulated charge via wiring or the like. The gate of the reset transistor TR1 _rst is electrically connected to the reset signal line RST1 and further to the above-mentioned vertical driving circuit part 32 . In addition, the other one of the drain/source of the reset transistor TR1 _rst (not connected to the side of the lower electrode 206 ) is electrically connected to the power circuit V _DD .

Furthermore, the lower electrode 206 is electrically connected via wiring to the gate of the amplifying transistor TR1 _amp that converts electric charge into voltage and outputs it as a pixel signal. In addition, node FD ₁ connected to one of the lower electrode 206, the gate of the amplification transistor TR1 _amp , and the drain/source of the reset transistor TR1 _rst constitutes a part of the reset transistor TR1 _rst . The charge from the lower electrode 206 changes the potential of the node _FD1 and is converted into a voltage by the amplification transistor TR1 _amp . In addition, one of the source and drain of the amplification transistor TR1 _amp is electrically connected via wiring to the source and drain of the selection transistor TR1 _sel which outputs the pixel signal obtained by converting the signal line VSL1 in accordance with the selection signal. The ultimate one. Furthermore, the other of the source/drain of the amplification transistor Tr1 _amp (not connected to the side of the selection transistor TR1 _sel ) is electrically connected to the power circuit V _DD .

Furthermore, the other of the source/drain of the selection transistor TR1 _sel (the side not connected to the amplification transistor TR1 _amp ) is electrically connected to the above-mentioned signal line VSL1 that transmits the converted voltage as a pixel signal, and then Electrically connected to the above-mentioned row signal processing circuit unit 34. In addition, the gate electrode of the selection transistor TR1 _sel is electrically connected to the selection line SEL1 that selects the column to output the pixel signal, and is further electrically connected to the above-mentioned vertical driving circuit section 32 .

Next, the equivalent circuit of the PD 300 provided in the semiconductor substrate 500 will be described with reference to FIG. 3 . As shown in FIG. 3 , the PD 300 provided in the semiconductor substrate 500 is electrically connected to the pixel transistors (amplification transistor TR2 _amp , transmission transistor TR2 _trs , reset transistor TR2 _rst , etc.) provided in the semiconductor substrate 500 via wiring. Select transistor TR2 _sel ). Specifically, one of the PDs 300 is electrically connected to one of the source/drain of the transfer transistor TR2 _trs that transfers charges through wiring. Furthermore, the other of the source/drain of the transfer transistor TR2 _trs (the side not connected to the PD 300) and the one of the source/drain of the reset transistor TR2 _rst are electrically connected through wiring. In addition, the gate electrode of the transfer transistor TR2 _trs is electrically connected to the transfer gate line TG2 and further connected to the above-mentioned vertical drive circuit unit 32 . Furthermore, the other of the source/drain of the reset transistor TR2 _rst (the side not connected to the transfer transistor TR2 _trs ) is electrically connected to the power circuit V _DD . Furthermore, the gate of the reset transistor TR2 _rst is electrically connected to the reset line RST2 and further connected to the above-mentioned vertical driving circuit part 32 .

Furthermore, the other of the source/drain of the transfer transistor TR2 _trs (the side not connected to the PD 300) is also electrically connected via wiring to the amplification transistor TR2 that amplifies (converts) the charge and outputs it as a pixel signal. The gate of _amp . In addition, one of the source and drain of the amplification transistor TR2 _amp is electrically connected via wiring to one of the source and drain of the selection transistor TR2 _sel that outputs the pixel signal to the signal line VSL2 in accordance with the selection signal. Furthermore, the other of the source/drain of the amplification transistor TR2 _amp (the side not connected to the selection transistor TR2 _sel ) is electrically connected to the power circuit V _DD . In addition, the other of the source/drain of the selection transistor TR2 _sel (the side not connected to the amplification transistor TR2 _amp ) is electrically connected to the above-mentioned signal line VSL2, and further is electrically connected to the above-mentioned row signal processing circuit section 34. Furthermore, the gate electrode of the selection transistor TR2 _sel is electrically connected to the selection line SEL2 and further to the above-mentioned vertical driving circuit part 32 .

In addition, since the PD 400 disposed in the semiconductor substrate 500 like the PD 300 can also be shown in the same equivalent circuit as the equivalent circuit of FIG. 3 , the description of the equivalent circuit of the PD 400 is omitted here.

＜＜3. Regarding the multilayer structure of the solid-state imaging element 100 >> The equivalent circuits of the PDs 200, 300, and 400 included in the solid-state imaging element 100 of this embodiment have been described above. Next, the multilayer structure of the solid-state imaging element 100 according to the embodiment of the present invention will be described with reference to FIG. 4 . FIG. 4 is a cross-sectional view of the solid-state imaging element 100 of this embodiment. Specifically, it is a cross-sectional view of the solid-state imaging element 100 when the solid-state imaging element 100 is cut along the penetrating direction of the through-electrode 600. In FIG. 4, the incidence of light with respect to the solid-state imaging element 100 is shown. The solid-state imaging element 100 is illustrated with the surface facing upward. In the following description, the stacked structure of the solid-state imaging element 100 will be described in order from the semiconductor substrate 500 located below the solid-state imaging element 100 toward the PD 200 located above the semiconductor substrate 500 .

First, as shown in FIG. 4 , in the solid-state imaging element 100 of this embodiment, two semiconductor regions 510 and 512 having a second conductivity type (for example, N type) are stacked in the thickness direction (depth direction) of the semiconductor substrate 500 . Formed in a semiconductor region 502 having a first conductivity type (for example, P type) of a semiconductor substrate 500 including silicon. The semiconductor regions 510 and 512 formed as described above become two stacked PDs 300 and 400 by forming a PN junction. For example, the PD 300 in which the semiconductor region 510 is a charge storage region is a photoelectric conversion element that absorbs blue light (eg, wavelength 450 nm to 495 nm) and generates (photoelectric conversion) charges, and the semiconductor region 512 is a charge storage region. The PD 400 is a photoelectric conversion element that absorbs red light (for example, wavelength 620 nm ~ 750 nm) and generates charges.

In addition, a wiring layer 520 is provided on the surface opposite to the incident surface of the semiconductor substrate 500 on which the PD 200 and the like are laminated (the lower side in FIG. 4 ). Furthermore, the wiring layer 520 is provided with gate electrodes 524 of a plurality of pixel transistors for reading charges accumulated in the PDs 200, 300, and 400, a plurality of wirings 522, and an interlayer insulating film 530. For example, the gate electrode 524 and the wiring 522 may be formed of materials such as tungsten (W), aluminum (Al), copper (Cu), or the like. In addition, the interlayer insulating film 530 may be formed of silicon oxide (SiO ₂ ), silicon nitride (SiN), or the like.

In addition, the semiconductor substrate 500 is provided with a through-electrode 600 penetrating the semiconductor substrate 500 for extracting charges generated by photoelectric conversion in the PD 200 to be described later toward a floating diffusion 514 to be described later. Specifically, in addition to doped silicon materials such as PDAS (Phosphorus Doped Amorphous Silicon), the conductor 602 that becomes the central axis of the through electrode 600 can also be made of aluminum, tungsten, or titanium (Ti). , cobalt (Co), hafnium (Hf), tantalum (Ta) and other metal materials. In order to suppress short circuit with the semiconductor region 502, an insulating film 604 containing _SiO2, SiN, etc. is formed on the outer periphery of the conductor 602. Furthermore, in this embodiment, a barrier metal film (not shown) may be provided between the conductor 602 and the insulating film 604 surrounding the outer periphery of the conductor 602. The barrier metal film can be formed of materials such as titanium nitride (TiN), tungsten nitride (WN), Ti, tantalum nitride (TaN), Ta, etc.

In addition, the through-electrode 600 may be connected to the floating diffusion 514 provided in the semiconductor region of the second conductivity type (for example, N type) provided in the semiconductor substrate 500 via the wiring 522 provided in the wiring layer 520 . That is, the above-mentioned through electrode 600 can electrically connect the PD 200 (specifically, the lower electrode 206 ) and the floating diffusion 514 . Furthermore, the floating diffusion 514 can utilize the through-electrode 600 to temporarily accumulate charges generated by photoelectric conversion of the PD 200 .

As described above, the wiring layer 520 is provided with a plurality of gate electrodes 524 as gate electrodes of a plurality of pixel transistors that read out charges generated by the PD 200 . Specifically, the electrode 524 is disposed to face the semiconductor region 502 of the first conductivity type (for example, P type) in the semiconductor substrate 500 via the insulating film 540 . Furthermore, within the semiconductor substrate 500, a semiconductor region 516 having a second conductivity type (for example, N type) is provided sandwiching the semiconductor region 502 having the first conductivity type. The semiconductor region 516 serves as the pixel transistor. It functions in the source/sink area. The above-mentioned through electrode 600 can also electrically connect the PD 200 (specifically, the lower electrode 206) and the pixel transistors. In addition, the detailed structure of the through-electrode 600 will be described later.

Furthermore, a fixed charge film 550 having negative fixed charges may be formed on the incident surface of the semiconductor substrate 500 . The fixed charge film 550 may be made of, for example, hafnium oxide (HfO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO), tantalum oxide (Ta ₂ O ₅ ), titanium oxide (TiO ₂ ), lanthanum oxide (La ₂ O ₃ ), cerium oxide (Pr ₆ O ₁₁ ), cerium oxide (CeO ₂ ), neodymium oxide (Nd ₂ O ₃ ), cadmium oxide (Pm ₂ O ₃ ), samarium oxide (Sm ₂ O ₃ ), europium oxide (Eu) ₂ O ₃ ), gallium oxide (Gd ₂ O ₃ ), gallium oxide (Tb ₂ O ₃ ), dysprosium oxide (Dy ₂ O ₃ ), gallium oxide (Ho ₂ O ₃ ), gallium oxide (Tm ₂ O ₃ ), Ytterbium oxide (Yb ₂ O ₃ ), ytterbium oxide (Lu ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), aluminum nitride (AlN), hafnium oxynitride (HfON), and aluminum oxynitride (AlON) are formed . In addition, the fixed charge film 550 may be a laminated film combining the above-mentioned different materials.

An insulating film 552 is provided on the fixed charge film 550 . The insulating film 552 may be formed of an insulating dielectric film such as SiO ₂ , TEOS (Tetraethyl Orthosilicate), silicon nitride (Si ₃ N ₄ ), silicon oxynitride (SiON), or the like.

The photoelectric conversion film 204 is provided in a multilayer structure sandwiched between the upper electrode 202 and the lower electrode 206 with the insulating film 560 interposed on the insulating film 552 . The upper electrode 202, the photoelectric conversion film 204, and the lower electrode 206 constitute the PD 200 that converts light into electric charges. The PD 200 is, for example, a photoelectric conversion element that absorbs green light (eg, wavelength 495 nm to 570 nm) and generates (photoelectric conversion) charges. In addition, the upper electrode 202 and the lower electrode 206 may be formed of a transparent conductive film such as indium tin oxide (ITO) or indium zinc oxide (IZO). Specifically, the upper electrode 202 may be configured to be shared by a plurality of adjacent pixels (the solid-state imaging element 100 ), while the lower electrode 206 may be configured individually for each plurality of pixels. Furthermore, the lower electrode 206 is electrically connected to the above-mentioned through electrode 600 through the metal wiring 570 penetrating the insulating film 560 . In addition, the metal wiring 570 may be formed of a metal material such as W, Al, Cu, or the like. Furthermore, the insulating film 560 may be formed of a light-transmissive insulating material such as Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , SiON, or the like.

Furthermore, as shown in FIG. 4 , a high refractive index layer 580 and a planarizing film 582 including an inorganic film such as Si ₃ N ₄ , SiON, silicon carbide (SiC), etc. are provided on the upper electrode 202 . In addition, an on-wafer lens 590 is provided on the planarizing film 582 . The on-wafer lens 590 may be formed of, for example, Si ₃ N ₄ or a resin material such as styrene resin, acrylic resin, styrene-acrylic copolymer resin, or silicone resin.

As described above, the solid-state imaging element 100 of this embodiment has a multilayer structure in which PDs 200, 300, and 400 respectively corresponding to three colors of light are laminated. That is, the above-mentioned solid-state imaging element 100 can be said to photoelectrically convert green light above the semiconductor substrate 500, in other words, in the photoelectric conversion film 204 (PD 200) formed on the incident surface side of the semiconductor substrate 500, and convert blue and The red light is photoelectrically converted in the PDs 300 and 400 in the semiconductor substrate 500 and is a longitudinal direction spectroscopic solid-state imaging element. Furthermore, the solid-state imaging element 100 of this embodiment can be said to be a back-illuminated CMOS solid-state imaging element having pixel transistors formed on the side opposite to the incident surface side.

In addition, the above-mentioned photoelectric conversion film 204 may be formed of an organic material (organic photoelectric conversion film) or an inorganic material (inorganic photoelectric conversion film). For example, when the photoelectric conversion film 204 is formed of an organic material, any one of the following four aspects can be selected, namely: (a) P-type organic semiconductor material, (b) N-type organic semiconductor material, (c) P-type At least two laminated structures among an organic semiconductor material layer, an N-type organic semiconductor material layer, and a mixed layer (heterostructure) of a P-type organic semiconductor material and an N-type organic semiconductor material, and (d) a P-type organic semiconductor material and an N-type organic semiconductor material. Mixed layer of organic semiconductor materials.

Specifically, examples of P-type organic semiconductor materials include naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, fused tetraphenyl derivatives, fused pentaphenyl derivatives, and quinacridone. Derivatives, thiophene derivatives, thienothiophene derivatives, benzothiophene derivatives, benzothienobenzothiophene derivatives, triallylamine derivatives, carbazole derivatives, perylene derivatives, pyrene derivatives, Phthalocyanine derivatives, fluoranthene derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, tetrazoporphine derivatives, metal complexes using heterocyclic compounds as ligands, polythiophene derivatives, polythiophene derivatives, Benzothiadiazole derivatives, polyfluoride derivatives, etc.

Examples of N-type organic semiconductor materials include fullerenes and fullerene derivatives (for example, C60, C70, C74, etc. fullerenes (high carbon fullerenes), internal fullerenes, etc.) or Fullerene derivatives (such as fullerene fluoride or PCBM (Phenyl-C ₆₁ -Butyric Acid Methyl Ester, phenyl-C ₆₁ -butyric acid methyl ester) fullerene compounds, fullerene polymers, etc.)〉 , Compared with P-type organic semiconductors, HOMO (Highest Occupied Molecular Orbital, the highest occupied molecular orbital) and LUMO (Lowest Unoccupied Molecular Orbital, the lowest unoccupied molecular orbital) are deep organic semiconductors, transparent inorganic metal oxides, etc. More specifically, examples of N-type organic semiconductor materials include organic molecules, organometallic complexes, or subphthalocyanine derivatives in which a part of the molecular skeleton is Heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms, such as pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, and isoquinoline derivatives , acridine derivatives, phenazine derivatives, phenanthroline derivatives, tetrazole derivatives, pyrazole derivatives, imidazole derivatives, thiazole derivatives, oxazole derivatives, imidazole derivatives, benzimidazole derivatives, benzene Triazole derivatives, benzoxazole derivatives, benzoxazole derivatives, carbazole derivatives, benzofuran derivatives, dibenzofuran derivatives, porphyrylene tetrazine derivatives, polyphenylene Vinyl derivatives, polybenzothiadiazole derivatives, polyfluoride derivatives, etc. Examples of groups contained in fullerene derivatives include branched or cyclic alkyl groups or phenyl groups; groups having linear or condensed aromatic compounds; and groups having halides. ; Partially fluoroalkyl; perfluoroalkyl; silyl; silyl alkoxy; aryl silyl; arylthio; alkylthio; arylsulfonyl; alkylsulfonyl; aryl sulfide material group; alkyl sulfide group; amine group; alkylamino group; arylamine group; hydroxyl; alkoxy group; acylamino group; acyloxy group; carbonyl group; carboxyl group; carboxamide group; alkyl group Oxycarbonyl group; acyl group; sulfonyl group; nitrile group; nitro group; group with chalcogenide; phosphine group; phosphine group; and derivatives thereof. In addition, the film thickness of the photoelectric conversion film 204 formed of an organic material is not limited, but may be, for example, 1×10 ^-8 m to 5×10 ^-7 m, preferably 2.5×10 ^-8 m to 3×10 ^{- 7} m, preferably 2.5×10 ^-8 m to 2×10 ^-7 m. In the above description, organic semiconductor materials are classified into P-type and N-type. However, here, the P-type means that positive holes are easily transported, and the N-type means that electrons are easily transported. That is, in organic semiconductor materials, like inorganic semiconductor materials, the explanation is not limited to having positive holes or electrons as a plurality of thermally excited carriers.

Furthermore, in detail, in order to function as the photoelectric conversion film 204 of the PD 200 that receives green light and performs photoelectric conversion, the photoelectric conversion film 204 may include, for example, a rose red pigment, a merocyanine pigment, or a quinacridone. Derivatives, and subphthalocyanine pigments (subphthalocyanine derivatives), etc.

If the photoelectric conversion film 204 is formed of an inorganic material, examples of the inorganic semiconductor material include crystalline silicon, amorphous silicon, microcrystalline silicon, crystalline selenium, amorphous selenium, and chalcopyrite-based compound CIGS (CuInGaSe). , CIS ( _{CuInSe 2} ), CuInS ₂ , CuAlS ₂ , CuAlSe ₂ , CuGaS 2 , CuGaSe ₂ , AgAlS ₂ , AgAlSe ₂ , AgInS ₂ , AgInSe ₂ , or III-V compounds of GaAS, InP, AlGaAS, InGaP, AlGaInP , InGaASP, and even compound semiconductors such as CdSe, CdS, In ₂ Se ₃ , In ₂ S ₃ , Bi ₂ Se ₃ , Bi ₂ S ₃ , ZnSe, ZnS, PbSe, PbS, etc. In addition, quantum dots containing the above-mentioned materials can also be used as the photoelectric conversion film 204.

In addition, in this embodiment, the above-mentioned solid-state imaging element 100 is not limited to a structure in which the PD 200 having the photoelectric conversion film 204 provided above the semiconductor substrate 500 and the PDs 300 and 400 provided in the semiconductor substrate 500 are laminated. . For example, in this embodiment, the solid-state imaging element 100 may have a structure in which a PD 200 having a photoelectric conversion film 204 provided above the semiconductor substrate 500 and a PD 300 provided in the semiconductor substrate 500 are laminated. The structure of 2 PD 200 and 300. In addition, in this embodiment, the solid-state imaging element 100 may have a structure including two or three PDs 200 stacked above the semiconductor substrate 500 . In this case, each PD 200 may have a photoelectric conversion film 204. Furthermore, the photoelectric conversion film 204 may be formed of an organic semiconductor material or an inorganic semiconductor material. At this time, in order to function as the photoelectric conversion film 204 of the PD 200 that receives blue light and performs photoelectric conversion, the photoelectric conversion film 204 may include, for example, coumaric acid pigment, tris-8-hydroxyquinoline aluminum (Alq ₃ ), and merocyanine pigments, etc. In addition, in order to function as the photoelectric conversion film 204 of the PD 200 that receives red light and performs photoelectric conversion, the photoelectric conversion film 204 may include a phthalocyanine pigment, a subphthalocyanine pigment (subphthalocyanine derivative), or the like.

＜＜4. Process of completing the embodiment of the present invention>> Before describing the embodiment of the present invention in detail, the process by which the present inventors completed the embodiment of the present invention will be described using FIG. 5 . FIG. 5 is an explanatory diagram for explaining the process of creating the embodiment of the present invention. Specifically, the left side of FIG. 5 schematically shows a cross-section of the through-electrode 800 of the comparative example, and the right side of FIG. 5 schematically shows the cross-section of the through-electrode 800 of the present invention. Cross section of through-electrode 600 according to the embodiment. In addition, here, the comparative example means the through-electrode 800 which the present inventors repeatedly studied before completing the embodiment of this invention.

In addition, the inventors of the present invention have been exploring the provision of through-electrodes 600 (800) for each solid-state imaging element (pixel) 100. At this time, in order to ensure good sensitivity of the solid-state imaging element 100, it is preferable to ensure a wide light incident surface for incident light. In other words, it is preferable to ensure a wide area occupied by the PDs 300 and 400. Therefore, when providing the through-electrode 600 for each solid-state imaging element 100, in order to secure a wide light incident surface for light to enter, the through-electrode 600 is preferably finer (for example, smaller in diameter). According to the discussion of the present inventors, the diameter of the conductor 602 (802) of the penetrating electrode 600 is preferably about 100 nm, for example. Therefore, the present inventors found that it is difficult to suppress the resistance value of the through-electrode 800 as a result of producing the through-electrode 800 of the comparative example having the through-electrode structure disclosed in the above-mentioned Patent Document 1 and having the smaller diameter as described above. lower.

Specifically, in addition to creating the embodiment of the present invention, the present inventors produced the fine through-electrode 800 (comparative example) as follows. First, as shown on the left side of FIG. 5 , a through hole 806 is formed that penetrates the semiconductor substrate 500 substantially perpendicularly to the semiconductor substrate 500 . Furthermore, an insulating film 804 is formed to cover the inner wall of the through hole 806 . Next, the conductor 802 is deposited by using a CVD (Chemical Vapor Deposition) method to bury the through hole 806 .

According to examination by the present inventors, it was found that when the conductor 802 is deposited so as to bury the through hole 806, a void 808 is generated in the through hole 806 as shown on the left side of FIG. 5 . The gap 808 is estimated to be generated as follows. It is known that when a film is deposited using the CVD method, the film is deposited to follow the shape of the substrate. Furthermore, it is known that when a film is deposited by the CVD method to bury the through-hole 806, the film is more likely to adhere to the upper portion of the inner wall of the through-hole 806. Therefore, the upper portion of the inner wall of the through-hole 806 and the lower portion of the inner wall are known to be There is a tendency for films to accumulate easily. Therefore, it is presumed that when the conductor 802 is deposited so as to bury the through hole 806, the pendant conductor 802 extending from the upper portion of the inner wall of the through hole 806 is easily formed. Furthermore, it is estimated that as the deposition of the conductor 802 proceeds, a film of the conductor 802 is further formed in a pendant shape on the above-described pendant film. Finally, the deposited conductor 802 forms a cover and generates a film in the through hole 806 . Void808. That is, in the comparative example, as shown on the left side of FIG. 5 , although the upper part of the through hole 806 is closed by the conductor 802 , a void 808 remains inside the through hole 806 . In other words, the through hole 806 cannot be closed by the conductor 802 . The situation of being buried. At this time, since the through hole 806 cannot be filled with the conductor 802, the resistance value of the through electrode 800 increases. According to the investigation by the present inventors, it is found that the above-mentioned phenomenon occurs more significantly as the through-electrode 800 becomes smaller and the aspect ratio of the through-hole 806 becomes larger.

Therefore, in view of the above-mentioned situation, in order to suppress the resistance value of the through-electrode 600 to a low value, the inventors devised a method to bury the through-hole 606 with the conductor 602 to avoid the void 808 occurring in the through-hole 606 . Embodiments of the present invention related to the through-electrode 600 .

In the comparative example, as shown on the left side of FIG. 5 , the cross-sectional area of the conductor 802 of the through-electrode 800 perpendicular to the penetration direction of the through-electrode 600 is constant, and the conductor 802 is cylindrical. On the other hand, in the embodiment of the present invention, as shown on the right side of FIG. 5 , in the upper part of the through-electrode 600 (the end on the PD 200 side), the cross-section of the conductor 602 is orthogonal to the penetration direction of the through-electrode 600 . The cross-sectional area gradually increases upward along the penetration direction. That is, in this embodiment, the upper part of the conductor 602 has a tapered shape. More specifically, in this embodiment, when producing the through-electrode 600 having the conductor 602 with a tapered shape as described above, the diameter of the upper part of the through-hole 606 is enlarged in a state where the inner wall is covered with the insulating film 604. The conductor 602 is deposited so as to bury the enlarged diameter through-hole 606 . According to this embodiment, by enlarging the diameter of the upper part of the through hole 606, the conductor 602 can easily reach the bottom of the through hole 606. Therefore, the embeddability of the conductor 602 can be improved and the occurrence of problems in the through hole 606 can be avoided. Void808. As a result, according to this embodiment, the resistance value of the through-electrode 600 can be suppressed to a low value. Hereinafter, details of the embodiments of the present invention will be described in sequence.

＜＜5. First embodiment＞＞ <5.1 Detailed structure of through-electrode 600> First, the detailed structure of the through-electrode 600 according to the first embodiment of the present invention will be described with reference to FIGS. 6 to 8 . FIG. 6 is a partially enlarged view of the cross section (FIG. 4) of the solid-state imaging element 100 of this embodiment. Specifically, it is an enlarged view of the through-electrode 600 and the surroundings of the through-electrode 600. 7 is a cross-sectional view of the through-electrode 600 taken along line A-A′ and line B-B′ in FIG. 6 . Specifically, the upper section of FIG. 7 shows a cross-sectional view of the through-electrode 600 taken along line A-A′ in FIG. 6 , and the lower section of FIG. 7 shows a cross-sectional view of the through-electrode 600 taken along line B-B′ of FIG. 6 . Furthermore, FIG. 8 shows a schematic diagram of the upper part of the through-electrode 600 in this embodiment. Specifically, it is a partially enlarged view of a cross-section of the through-electrode 600 when the through-electrode 600 is cut along its penetration direction. In addition, in FIG. 8 , the illustration of the fixed charge film 650 is omitted for easy understanding.

As shown in FIG. 6 , the through electrode 600 of this embodiment mainly includes a through hole 606 that penetrates the semiconductor substrate 500 substantially perpendicularly to the semiconductor substrate 500 (in other words, penetrates in the film thickness direction of the semiconductor substrate 500 ), and a covering through hole 606 . There is a fixed charge film 650 on the inner wall, an insulating film 604 covering the inner wall via the fixed charge film 650, and a conductor 602 embedded in the through hole 606. In addition, as described above, a barrier metal film (not shown) may be provided between the conductor 602 and the insulating film 604 surrounding the outer periphery of the conductor 602 . In the following, the details of each part of the through-electrode 600 will be described in sequence.

In this embodiment, the above-mentioned through hole 606 is, for example, a cylindrical or a truncated cone-shaped hole with a tapered shape, and is preferably a cylindrical or substantially cylindrical hole (in other words, a hole with an opening diameter that is approximately the same in the through direction). . In this embodiment, by forming the through-hole 606 into a substantially cylindrical hole, the film thickness of the insulating film 604 covering the inner wall of the through-hole 606 can be made more uniform. Therefore, according to this embodiment, it is possible to ensure the insulation between the through-electrode 600 (specifically, the conductor 602) and the semiconductor substrate 500 (specifically, the semiconductor region 502), and to reduce the parasitic capacitance of the through-electrode 600 caused by the insulating film 604. . As a result, according to this embodiment, since the above-mentioned parasitic capacitance can be reduced, unintentional transmission of noise to the through-electrode 600 via the parasitic capacitance can be avoided, and even deterioration of the characteristics of the solid-state imaging element 100 can be avoided.

In this embodiment, the fixed charge film 650 is provided to cover the inner wall and the bottom surface (lower surface) of the through hole 606 as described above. The fixed charge film 650 can be formed of HfO ₂ , Al ₂ O ₃ , ZrO, Ta ₂ O ₅ , TiO ₂ or the like, for example, similarly to the above-described fixed charge film 550 . In addition, the fixed charge film 650 may be a laminated film combining the different materials mentioned above.

In this embodiment, the insulating film 604 is provided to cover the inner wall of the through hole 606 via the fixed charge film 650 as described above. In addition, the insulating film 604 is provided to cover the outer periphery of the conductor 602 described later. In addition, the insulating film 604 is an insulating film for suppressing a short circuit with the semiconductor substrate 500 (specifically, the semiconductor region 502 ), and is formed of SiO _{2 ,} SiN, or the like.

In this embodiment, the conductor 602 is embedded in the through hole 606 whose inner wall is covered by the fixed charge film 650 and the insulating film 604 . In other words, the conductor 602 is located at the center of the through-electrode 600 as shown in FIG. 6 . Specifically, the conductor 602 is a substantially cylindrical electrode that penetrates the center of the through hole 606 and has a tapered shape at its upper portion (the end on the PD 200 side). Furthermore, the conductor 602 penetrates the bottom surface (lower surface) of the through hole 606 and extends to the wiring 522 of the wiring layer 520 . As explained above, the conductor 602 may be made of metal materials such as Al, W, Ti, Co, Hf, Ta, etc., in addition to doped silicon materials such as PDAS.

More specifically, regarding the conductor 602 , in the upper part of the through-electrode 600 (the end on the PD 200 side), the cross-sectional area of the conductor 602 perpendicular to the penetration direction of the through-electrode 600 gradually increases upward along the penetration direction. increase. That is, in this embodiment, the upper side of the conductor 602 has a tapered shape.

Furthermore, referring to FIG. 7 , the conductor 602 will be described in more detail. The lower part of FIG. 7 shows a cross-section when the through-electrode 600 is cut below the fixed charge film 550 with a plane (line BB′ in FIG. 6 ) perpendicular to the penetration direction of the through-electrode 600 . 7 shows a cross section of the insulating film 552 when the through-electrode 600 is cut along a plane (line AA′ in FIG. 6 ) perpendicular to the penetrating direction of the through-electrode 600 . As shown in the upper view and the lower view of FIG. 7 , in this embodiment, the conductor 602 expands in diameter upward. More specifically, in this embodiment, the diameter of the conductor 602 in the cross section of the upper part of the through-electrode 600 (the end on the PD 200 side), in other words, the conductivity when the through-electrode 600 is cut along line AA′ in FIG. 6 The diameter D ₁ of the body 602 (refer to the upper side view of FIG. 7 ) is preferably the diameter of the conductor 602 in the cross section of the lower part of the through-electrode 600 (the end on the floating diffusion 514 side), in other words, BB´ in FIG. 6 The diameter D ₂ of the conductor 602 when the wire is cut through the electrode 600 (refer to the lower diagram in FIG. 7 ) is 1.2 times or more.

In addition, in this embodiment, when the through-electrode 600 is cut along line BB′ in FIG. 6, the diameter D ₂ of the conductor 602 (see the lower diagram in FIG. 7) is preferably 50 nm to 500 nm. Furthermore, in this embodiment, when the through-electrode 600 is cut along line AA′ in FIG. 6 , the diameter D ₁ of the conductor 602 (see the upper view of FIG. 7 ) is preferably 60 nm to 600 nm.

Moreover, the upper surface of the conductor 602 (the surface on the side of the PD 200) is preferably wider to ensure contact with the metal wiring 570. However, if the upper surface of the conductor 602 is widened, the light direction will be directed above the conductor 602. Incidence of the PDs 300, 400 located below the surface is hindered by the surface above the conductor 602. Therefore, in this embodiment, the upper surface of the conductor 602 is preferably narrow within a range that can ensure contact with the metal wiring 570 . In this embodiment, the upper surface of the conductor 602 is preferably wider than the cross section of the conductor 602 when the through-electrode 600 is cut along line A-A′ in FIG. 6 (see the upper side view in FIG. 7 ), and It is narrower than the opening of the through hole 606 (specifically, the opening of the through hole 606 in a state where the inner wall is not covered by the fixed charge film 650 and the insulating film 604).

Furthermore, in this embodiment, as shown in FIG. 8 which enlarges a part of the cross-section of the through-electrode 600 when the through-electrode 600 is cut along its penetrating direction, in the upper part of the through-electrode 600 (the end on the PD 200 side) The gradient of the outer peripheral surface of the conductor 602 of the penetration electrode 600 is preferably at an angle of not less than 1° and not more than 60° with respect to the central axis 610 of the conductor 602 extending in the penetration direction. Furthermore, in this embodiment, the gradient is preferably set to a thickness that ensures that the insulating film 604 can suppress a short circuit with the semiconductor substrate 500 (specifically, the semiconductor region 502 ) and ensures a wider light direction toward the PD. 300, 400 The value of the incident light incident surface.

In addition, in this embodiment, the conductor 602 only needs to have a tapered shape on the upper part of the through-electrode 600 (the end on the PD 200 side). Film thickness) has a tapered shape and is not specifically limited.

In this embodiment, details will be described later. However, when forming the through-electrode 600 having the conductor 602 having the above-described shape, the upper part of the through-hole 606 with the inner wall covered by the insulating film 604 is enlarged in diameter. , the conductor 602 is deposited so as to bury the enlarged through-hole 606 . According to this embodiment, by enlarging the diameter of the upper part of the through-hole 606, the conductor 602 can easily reach the bottom of the through-hole 606, thereby improving the embeddability of the conductor 602 and avoiding the occurrence of problems in the through-hole 606. Void808. As a result, according to this embodiment, the resistance value of the through-electrode 600 can be suppressed to a low value.

<5.2 About the manufacturing method of the solid-state imaging element 100> The detailed structure of the through-electrode 600 of this embodiment has been described above. Next, a method of manufacturing the solid-state imaging element 100 including the through-electrode 600 of this embodiment will be described with reference to FIGS. 9 to 13 . 9 to 13 are explanatory diagrams for explaining the manufacturing method of the solid-state imaging element 100 of this embodiment, showing cross-sections of the solid-state imaging element 100 in each step of the manufacturing method corresponding to the cross-sectional view of FIG. 4 .

First, as shown in FIG. 9 , the semiconductor substrate 500 is processed from the light incident surface side by, for example, dry etching to form a through hole 606 a penetrating the semiconductor substrate 500 .

Then, as shown in FIG. 10 , fixed charge films 550 and 650 and insulating films 552 and 604 are formed to cover the inner wall and bottom surface of the through hole 606 a and the incident surface of the semiconductor substrate 500 .

Then, as shown in FIG. 11 , parts of the fixed charge film 650 and the insulating films 552 and 604 are removed by, for example, dry etching to form a through hole 606 b that penetrates the semiconductor substrate 500 and extends to the wiring 522 . At this time, part of the insulating films 552 and 604 formed around the opening on the upper side of the through-hole 606b is removed, and the diameter of the opening on the upper side of the through-hole 606b is enlarged.

Next, as shown in FIG. 12 , a conductor 602 (metal film) is formed so as to bury the through hole 606 b. In addition, at this time, as will be described later, when the through hole 606b is viewed from above, the conductor 602 may be in a recessed state at the center of the through hole 606b.

Then, as shown in FIG. 13 , a part of the conductor 602 is removed by dry etching, for example, to form a through-electrode 600 .

Furthermore, metal wiring 570 and insulating film 560 are formed. After that, the lower electrode 206, the photoelectric conversion film 204, the upper electrode 202, the high refractive index layer 580, and the like are formed. Finally, the planarization film 582 and the on-wafer lens 590 are formed. Then, based on the above content, the solid-state imaging element 100 shown in FIG. 4 can be obtained.

In addition, the solid-state imaging element 100 of this embodiment can be manufactured by using methods, equipment, and conditions used in the manufacturing of general semiconductor devices. That is, the solid-state imaging element 100 of this embodiment can be manufactured using the following conventional semiconductor device manufacturing method.

Examples of the manufacturing method include physical chemical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD). Examples of the PVD method include vacuum evaporation, EB (electron beam) evaporation, various sputtering methods (magnetron sputtering, RF-DC coupled bias sputtering, ECR (Electron Cyclotron Resonance), Cyclotron resonance) sputtering method, opposed target sputtering method, high frequency sputtering method, etc.), ion plating method, laser ablation method, molecular beam epitaxy method (MBE method), laser transfer printing method. Examples of the CVD method include plasma CVD method, thermal CVD method, organic metal (MO) CVD method, photo CVD method, and the like. Examples of other methods include electroplating, electroless plating, spin coating, dipping, pouring, micro-contact printing, droplet pouring, screen printing, inkjet printing, and offset printing. Various printing methods such as printing method, gravure printing, flexographic printing method; embossing method; spray coating method; and air knife coater method, blade coater method, rod coater method, knife type coating method, press Extrusion coater method, reverse roll coater method, transfer roll coater method, gravure coating method, kiss coater method, pour coater method, spray coater method, slit coater method, Various coating methods such as calender coater method. Examples of patterning methods include shadow masking, laser transfer, chemical etching such as photolithography, and physical etching using ultraviolet rays or lasers. In addition, examples of planarization techniques include CMP (Chemical Mechanical Polishing) method, laser planarization method, reflow method, and the like.

As described above, in this embodiment, when manufacturing the through-electrode 600 having the conductor 602, the diameter of the upper part of the through-hole 606a in the state where the inner wall is covered with the insulating film 604 is expanded, so that the diameter of the expanded through-hole is The conductor 602 is accumulated by embedding 606b. According to this embodiment, by enlarging the diameter of the upper part of the through hole 606a, the conductor 602 can easily reach the bottom of the through hole 606b. Therefore, the embeddability of the conductor 602 can be improved, and the occurrence of problems in the through hole 606b can be avoided. Void808. As a result, according to this embodiment, the resistance value of the through-electrode 600 can be suppressed to a low value.

＜5.3 Variations＞ The upper part of the conductor 602 (the end on the PD 200 side) of the solid-state imaging element 100 of this embodiment can be electrically connected to a wiring including a transparent conductor. In other words, in this embodiment, the metal wiring 570 in FIG. 4 can be formed of a transparent conductor.

Hereinafter, the manufacturing method of the solid-state imaging element 100 of this modification will be described with reference to the above-mentioned FIG. 13 . As shown in FIG. 13 , a part of the conductor 602 is removed by, for example, dry etching to form a through-electrode 600 , and then a transparent conductor is formed on the through-electrode 600 . Furthermore, the wiring 570 of the solid-state imaging element 100 of this modification can be formed by removing part of the transparent conductor by, for example, dry etching to form a wiring structure. In addition, the above-mentioned transparent conductor may be formed of materials such as ITO and IZO.

In this variation, by forming the metal wiring 570 using a transparent conductor, it is possible to prevent the light incident on the wiring 570 from being reflected and unintentionally incident on the PDs 200 , 300 , and 400 , thereby reducing the amount of light incident on the solid-state imaging element 100 . The production of mixed colors or flashes.

＜＜6. Second embodiment＞＞ In the embodiment of the present invention, the through-electrode 600 of the first embodiment described above can be further modified. Hereinafter, the through electrode 600a according to the second embodiment of the present invention will be described with reference to FIGS. 14 and 15 . FIG. 14 is a cross-sectional view of the solid-state imaging element 100a of the present embodiment. Specifically, it is a cross-sectional view of the solid-state imaging element 100a when the solid-state imaging element 100a is cut along the penetration direction of the through-electrode 600a. 15 is a schematic diagram of the upper part of the through-electrode 600a in this embodiment. Specifically, it is a partial cross-sectional view of the through-electrode 600a when it is cut along the penetration direction of the through-electrode 600a. In addition, in FIG. 15 , the illustration of the fixed charge film 650 is omitted for easy understanding.

As shown in FIG. 14, in the cross-section of the solid-state imaging element 100a, the conductor 602a of the through-electrode 600a in this embodiment is located above the through-electrode 600a (the end on the PD 200 side), more specifically, between the through-electrode 600a. The upper end (end surface on the PD 200 side) has two branch portions (first branch portions) 602b branched from the central axis (not shown in FIG. 14 ) of the conductor 602a. In this embodiment, the branch portion 602b is curved in a circular arc drawn from the central axis.

Specifically, as shown in FIG. 15 , which is an enlarged view of the through-electrode 600 a in this embodiment, the upper part of the conductor 602 a (the end on the PD 200 side) has a shape that expands with curvature toward the light incident surface of the semiconductor substrate 500 . In other words, in the enlarged view, the conductor 602a appears to have two branch portions 602b branched in arcs from the central axis 610 of the conductor 602a. In this embodiment, the curvature radius r of the branch portion 602b is preferably not less than 10 nm and not more than 1000 nm. That is, as in the first embodiment, the curvature radius r is preferably set so as to ensure that the insulating film 604 has a film thickness that can suppress a short circuit with the semiconductor substrate 500 (specifically, the semiconductor region 502 ) and can ensure a wider area. The value of the light incident surface where light is incident towards PD 300 and 400.

Furthermore, according to this embodiment, in the area of the arcuate branch portion 602b, from the opening end 606c on the upper side of the through hole 606 covered by the insulating film 604 and the fixed charge film 650 (not shown) to the conductor The distance L of 602a is uniform compared with the above-mentioned first embodiment. Therefore, in this embodiment, even if a high voltage is applied to the insulating film 604 and the fixed charge film 650, since insulation collapse is less likely to occur in the branch portion 602b, the withstand voltage of the insulating film 604 and the fixed charge film 650 can still be improved ( reliability).

Furthermore, in this embodiment, in the cross section of the solid-state imaging element 100a, the conductor 602a of the through-electrode 600a in this embodiment may have a conductor at the lower part of the through-electrode 600a (the end on the side of the floating diffusion 514). The central axis 610 of 602a branches into two branch portions (second branch portions) (illustration omitted). More specifically, in this embodiment, the conductor 602a may have two of the above-mentioned branch parts at the lower end (the end surface on the floating diffusion part 514 side) of the through-electrode 600a, for example. Furthermore, in the present embodiment, the branch portion penetrating the lower portion of the electrode 600a can be curved in an arc shape from the central axis 610 in the same manner as the branch portion 602b. Furthermore, at this time, the branch portion 602b at the upper portion of the through-electrode 600a may have a larger curvature radius r than the branch portion at the lower portion of the through-electrode 600a.

＜＜7. Third embodiment＞＞ In addition, in the embodiment of the present invention, the through-electrode 600 of the above-described first embodiment can be further modified. Hereinafter, the through electrode 600b according to the third embodiment of the present invention will be described with reference to FIG. 16 . FIG. 16 is a schematic diagram of the upper part of the through-electrode 600b in this embodiment. Specifically, it is a partially enlarged view of a cross-section of the through-electrode 600b when the through-electrode 600b is cut along the penetration direction. In addition, in FIG. 16 , the illustration of the fixed charge film 650 is omitted for easy understanding.

As shown in FIG. 16 , in the above-mentioned cross section, the conductor 602c of the through-electrode 600b of this embodiment has, like the above-mentioned third embodiment, the conductor 602c on the upper end (the end surface of the PD 200 side) of the through-electrode 600a. The two branch parts (first branch part) of the central axis branch 602c are 602d. In other words, the end of the conductor 602 c on the PD 200 side of this embodiment has a shape that extends with a curvature toward the light incident surface of the semiconductor substrate 500 . Furthermore, in this embodiment, as shown in FIG. 16 , the conductor 602c further has a recessed portion 620 located between the two branch portions 602d. That is, in this embodiment, when the through-hole 606 is viewed from above, the conductor 602c is in a recessed state at the center of the through-hole 606.

In this embodiment, by providing the recessed portion 620 between the two branch portions 602d, the contact area between the metal wiring 570 electrically connected to the through-electrode 600b and the conductor 602c can be widened, so that the metal wiring can be reduced 570 and the contact resistance of the conductor 602c.

＜＜8. Fourth Embodiment ＞＞ Furthermore, in the embodiment of the present invention, the PD 200 of the solid-state imaging element 100 of the above-described first embodiment can be further modified. Hereinafter, a solid-state imaging element 100b according to a fourth embodiment of the present invention will be described with reference to FIG. 17 . FIG. 17 is a cross-sectional view of the solid-state imaging element 100b of this embodiment. Specifically, it is a cross-sectional view of the solid-state imaging element 100b when the solid-state imaging element 100b is cut along the penetration direction of the through-electrode 600. In FIG. 17, the incidence of light with respect to the solid-state imaging element 100b is used. The solid-state imaging element 100b is illustrated with the surface facing upward.

In this embodiment, as shown in FIG. 17 , the PD 200 a disposed above the semiconductor substrate 500 has an upper electrode 202 , a photoelectric conversion film 204 , and a lower electrode 206 like the PD 200 of the first embodiment described above. In addition, in this embodiment, the PD 200a has the storage electrode 208 facing the upper electrode 202 via the photoelectric conversion film 204 and the insulating film 560. The storage electrode 208 is arranged separately from the lower electrode 206, and like the upper electrode 202 and the lower electrode 206, it can be formed of a transparent conductor such as ITO or IZO.

In the PD 200a of this embodiment, wirings (not shown) are electrically connected to the lower electrode 206 and the storage electrode 208 respectively, and a desired potential can be applied to each of the lower electrode 206 and the storage electrode 208 using the wirings. . Therefore, in this embodiment, by controlling the potential applied to the lower electrode 206 and the accumulation electrode 208, the photoelectric conversion film 204 can accumulate the charge generated in the photoelectric conversion film 204, or can extract the charge toward the floating diffusion portion 514. . In other words, the storage electrode 208 can function as a charge storage electrode for pulling charges generated in the photoelectric conversion film 204 in response to the applied potential and accumulating the charges in the photoelectric conversion film 204 .

In the PD 200 of the first embodiment described above, charges generated by photoelectric conversion of the photoelectric conversion film 204 are directly accumulated in the floating diffusion portion 514 via the lower electrode 206 and the through-electrode 600 . Due to the above-mentioned mechanism, it is difficult to completely deplete the photoelectric conversion film 204 . As a result, in the first embodiment, the kTC noise (reset noise) of the solid-state imaging element 100 becomes larger and the random noise deteriorates, resulting in a deterioration in imaging quality. On the other hand, in this embodiment, by providing the accumulation electrode 208, when the PD 200a is operating, the charges generated by the photoelectric conversion of each photoelectric conversion film 204 can be accumulated in the photoelectric conversion film 204, and The charge reaching each lower electrode 206 can be reset by being discharged out of the system. Furthermore, in the above operation, the charges accumulated in each photoelectric conversion film 204 can be transferred to each lower electrode 206 after resetting, and the charges transferred to each lower electrode 206 can be sequentially read out. Furthermore, during the operation of the PD 200a, the above-mentioned reset and read operations are repeatedly performed. That is, in this embodiment, when the exposure of the solid-state imaging element 100b starts, it is easy to completely deplete the floating diffusion portion 514 and erase the charge. As a result, according to this embodiment, it is possible to further suppress the occurrence of a phenomenon in which the kTC noise of the solid-state imaging element 100b increases and random noise deteriorates, resulting in a decrease in image quality.

＜＜9. Fifth embodiment＞＞ The above-mentioned solid-state imaging device 1 according to the embodiment of the present invention can be used in imaging devices such as digital still cameras and video cameras, mobile terminal devices with imaging functions, photocopiers using solid-state imaging elements as image reading units, etc. The camera device is used in all electronic equipment in the image capture part. Furthermore, embodiments of the present invention can also be applied to robots, drones, automobiles, medical equipment (endoscopes), etc. including the solid-state imaging device 1 described above. In addition, the solid-state imaging device 1 of this embodiment may be formed as a single chip, or may be in the form of a module with an imaging function in which an imaging unit and a signal processing unit or an optical system are packaged into one. Hereinafter, an example of an electronic device 900 including the imaging device 902 including the above-mentioned solid-state imaging device 1 will be described with reference to FIG. 18 as a fifth embodiment of the present invention. FIG. 18 is an explanatory diagram showing an example of the electronic device 900 of this embodiment.

As shown in FIG. 18 , the electronic device 900 includes an imaging device 902 , an optical lens 910 , a shutter mechanism 912 , a drive circuit unit 914 , and a signal processing circuit unit 916 . The optical lens 910 forms the image light (incident light) from the subject on the imaging surface of the imaging device 902 . Thereby, signal charges are accumulated in the solid-state imaging element 100 of the solid-state imaging device 1 of the imaging device 902 for a certain period of time. The shutter mechanism 912 controls the light irradiation period and the light blocking period of the imaging device 902 by opening and closing. The drive circuit unit 914 supplies drive signals for controlling the signal transmission operation of the imaging device 902 and the shutter operation of the shutter mechanism 912 to them. That is, the imaging device 902 performs signal transmission based on the drive signal (timing signal) supplied from the drive circuit unit 914 . The signal processing circuit unit 916 performs various signal processing. For example, the signal processing circuit unit 916 outputs the signal-processed image signal to a storage medium (not shown) such as a memory or to a display unit (not shown).

＜＜10.Summary＞＞ As explained above, according to each embodiment and modification example of the present invention, the resistance value of the through-electrode 600 can be suppressed to a low value.

In addition, in the above-described embodiment of the present invention, the solid-state imaging element 100 may have a structure having two or more PDs 200 stacked on the semiconductor substrate 500 . At this time, for example, as a through electrode for transmitting charges generated in the upper PD 200 among the two PDs 200 stacked above the semiconductor substrate 500 toward the floating diffusion 514 provided in the semiconductor substrate 500 , a through electrode may be used. The through electrode 600 of this embodiment is used.

In addition, in the above-mentioned embodiment of the present invention, the solid-state imaging element 100 in which the first conductivity type is the P type, the second conductivity type is the N type, and electrons are used as signal charges has been described. However, this invention The embodiment of the invention is not limited to this example. For example, this embodiment can be applied to the solid-state imaging element 100 in which the first conductivity type is N type, the second conductivity type is P type, and positive holes are used as signal charges.

Furthermore, in the above-described embodiments of the present invention, the semiconductor substrate 500 does not have to be a silicon substrate, but may be other substrates (such as an SOI (Silicon On Insulator) substrate or a SiGe substrate, etc.). In addition, the above-mentioned semiconductor substrate 500 may be one in which a semiconductor structure or the like is formed on the above-mentioned various substrates.

Furthermore, the solid-state imaging device 100 according to the embodiment of the present invention is not limited to a solid-state imaging device that detects the distribution of the incident light amount of visible light and captures an image. For example, this embodiment can be used for a solid-state imaging device that captures the distribution of incident amounts of infrared rays, X-rays, particles, etc. as an image, or for a fingerprint detection sensor that detects the distribution of other physical quantities such as pressure or electrostatic capacitance and captures the image. Applications of solid-state imaging elements (physical quantity distribution detection devices) such as detectors.

＜11. Application examples of endoscopic surgery system＞ The technology of the present invention (the present invention) can be applied to various products. For example, the technology of the present invention may be applied to endoscopic surgical systems.

FIG. 19 is a diagram showing an example of the schematic configuration of an endoscopic surgery system to which the technology of the present invention (the present invention) can be applied.

FIG. 19 illustrates a situation in which an operator (doctor) 11131 performs surgery on a patient 11132 on a hospital bed 11133 using the endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, a tracheostomy tube 11111, an energy treatment device 11112 and other surgical instruments 11110, a support arm device 11120 that supports the endoscope 11100, and a device for endoscopic surgery. Composed of 11200 trolleys with various devices for microscopic surgery.

The endoscope 11100 is composed of a barrel 11101 that is inserted into the body cavity of the patient 11132 with a specific length from the front end, and a camera head 11102 connected to the base end of the barrel 11101. In the illustrated example, the endoscope 11100 is configured as a so-called rigid scope having a rigid barrel 11101. However, the endoscope 11100 may be configured as a so-called flexible scope having a flexible barrel.

The front end of the lens barrel 11101 is provided with an opening in which an objective lens is embedded. The endoscope 11100 is connected to a light source device 11203. The light generated by the light source device 11203 is guided to the front end of the lens barrel by a light guide extending inside the lens barrel 11101, and is directed toward the observation of the body cavity of the patient 11132 through the objective lens. Object irradiation. In addition, the endoscope 11100 can be a straight-view mirror, a side-view mirror, or a side-view mirror.

An optical system and an imaging element are provided inside the camera head 11102, and the reflected light (observation light) from the observation object is collected on the imaging element by the optical system. The imaging element photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. This image signal is sent to the camera control unit (CCU: Camera Control Unit) 11201 as RAW data.

The CCU 11201 is composed of a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), etc., and collectively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102, and performs various image processing on the image signal for displaying an image based on the image signal, such as development processing (demosaic processing).

The display device 11202 displays an image based on the image signal processed by the CCU 11201 in accordance with the control from the CCU 11201 .

The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies irradiation light to the endoscope 11100 when photographing a surgical site or the like.

The input device 11204 is an input interface for the endoscopic surgery system 11000. The user can input various information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user inputs an instruction to change the imaging conditions of the endoscope 11100 (type of irradiation light, magnification, focal length, etc.).

The treatment instrument control device 11205 controls the driving of the energy treatment instrument 11112 for cauterizing tissue, incising or sealing blood vessels, and the like. In order to ensure the field of view of the endoscope 11100 and the operating space of the operator, the insufflation device 11206 inflates the body cavity of the patient 11132 and sends gas into the body cavity through the insufficiency tube 11111. The recorder 11207 is a device that can record various information related to surgery. Printer 11208 is a device that can print various information related to surgery in various forms such as text, images, or charts.

In addition, the light source device 11203 that supplies the endoscope 11100 with illumination light when photographing the surgical site may be composed of, for example, a white light source composed of an LED, a laser light source, or a combination thereof. If the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so the white balance of the captured image can be adjusted in the light source device 11203. In this case, by irradiating the observation object with laser light from each of the RGB laser light sources in a time-sharing manner, and controlling the drive of the imaging element of the camera head 11102 in synchronization with the irradiation timing, it is also possible to time-share photography with each of the RGB corresponding image. According to this method, a color image can be obtained even if a color filter is not provided in the imaging element.

In addition, the light source device 11203 can be driven so as to change the intensity of the output light at specific intervals. The driving of the imaging element of the camera head 11102 is controlled in synchronization with the timing of the change in the light intensity to obtain images in a time-sharing manner. By synthesizing the images, a high dynamic range image without underexposure or overexposure can be generated.

In addition, the light source device 11203 may be configured to provide light in a specific wavelength band corresponding to special light observation. In special light observation, for example, by taking advantage of the wavelength dependence of light absorption by biological tissues and irradiating light with a narrower frequency than the light irradiated during general observation (i.e., white light), high-contrast imaging of mucous membranes is performed The so-called narrow band imaging of specific tissues such as superficial blood vessels. Alternatively, in special light observation, fluorescence observation in which an image is obtained by irradiating fluorescence generated by excitation light can also be performed. In fluorescence observation, the biological tissue can be irradiated with excitation light to observe the fluorescence from the biological tissue (autofluorescence observation), or a reagent such as indocyanine green (ICG) can be locally injected into the biological tissue, and the The biological tissue is irradiated with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescence image, etc. The light source device 11203 may be configured to provide narrow-band light and/or excitation light corresponding to such special light observation.

FIG. 20 is a block diagram showing an example of the functional configuration of the camera head 11102 and CCU 11201 shown in FIG. 19 .

The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are communicably connected to each other through a transmission cable 11400.

The lens unit 11401 is an optical system provided at a connection portion with the lens barrel 11101. The observation light captured from the front end of the lens barrel 11101 is guided to the camera head 11102 and is incident on the lens unit 11401. The lens unit 11401 is composed of a plurality of lenses including a zoom lens and a focus lens.

The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be one (so-called single-board type) or a plurality of imaging elements (so-called multi-board type). When the imaging unit 11402 has a multi-plate structure, for example, each imaging element generates an image signal corresponding to each of RGB and combines them to obtain a color image. Alternatively, the imaging unit 11402 may be configured to include a pair of imaging elements for respectively acquiring right-eye and left-eye image signals corresponding to 3D (Dimensional) display. By performing 3D display, the operator 11131 can more accurately grasp the depth of the biological tissue at the surgical site. In addition, when the imaging unit 11402 has a multi-plate structure, a plurality of lens units 11401 may be provided corresponding to each imaging element.

In addition, the imaging unit 11402 does not necessarily need to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101 directly behind the objective lens.

The driving unit 11403 is composed of an actuator, and moves the zoom lens and the focus lens of the lens unit 11401 by a specific distance along the optical axis under control from the camera head control unit 11405. Thereby, the magnification and focus of the captured image captured by the imaging unit 11402 can be appropriately adjusted.

The communication unit 11404 is composed of a communication device for sending and receiving various information to and from the CCU 11201. The communication unit 11404 sends the image signal obtained from the camera unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies it to the camera head control unit 11405 . The control signal includes, for example, information that specifies the frame rate of the captured image, information that specifies the exposure value when capturing, and/or information that specifies the magnification and focus of the captured image, and the imaging conditions. Related information.

In addition, the above-mentioned imaging conditions such as frame rate, exposure value, magnification, and focus can be appropriately specified by the user, or can be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, an AF (Auto Focus) function, and an AWB (Auto White Balance) function.

The camera head control unit 11405 controls the driving of the camera head 11102 based on the control signal received from the CCU 11201 via the communication unit 11404.

The communication unit 11411 is composed of a communication device for sending and receiving various information to and from the camera head 11102 . The communication unit 11411 receives the image signal transmitted from the camera head 11102 via the transmission cable 11400.

Furthermore, the communication unit 11411 transmits a control signal for controlling the drive of the camera head 11102 to the camera head 11102 . Image signals or control signals can be sent through electrical communication or optical communication.

The image processing unit 11412 performs various image processing on the image signal sent from the camera head 11102 as RAW data.

The control unit 11413 performs various controls related to imaging of the surgical site, etc. by the endoscope 11100 and display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

Furthermore, the control unit 11413 causes the display device 11202 to display the captured image of the surgical site or the like based on the image signal processed by the image processing unit 11412. At this time, the control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, by detecting the shape or color of the edges of objects included in the captured image, the control unit 11413 can identify surgical instruments such as forceps, specific biological parts, bleeding, mist when using the energy treatment tool 11112, etc. . When causing the display device 11202 to display the captured image, the control unit 11413 may use the recognition result to display various surgical support information overlaid on the image of the surgical site. By overlaying and displaying the surgical support information, the surgeon 11131 is reminded, thereby reducing the burden on the surgeon 11131 and allowing the surgeon 11131 to perform the surgery accurately.

The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 may be an electrical signal cable corresponding to the communication of electrical signals, an optical fiber corresponding to the optical communication, or a composite cable thereof.

Here, in the example shown in the figure, the transmission cable 11400 can be used for wired communication, but the communication between the camera head 11102 and the CCU 11201 can be performed wirelessly.

As above, an example of the endoscopic surgery system to which the technology of the present invention can be applied has been described. The technology of the present invention can be applied to the endoscope 11100, the imaging unit 11402 of the camera head 11102, the image processing unit 11412 of the CCU 11201, and the like in the configuration described above. For example, the solid-state imaging device 1 shown in FIG. 1 can be applied to an endoscope 11100, an imaging unit 11402, an image processing unit 11412, and the like. By applying the technology of the present invention to the endoscope 11100, the imaging unit 11402, the image processing unit 11412, etc., a clearer image of the surgical site can be obtained, so the operator can confirm the surgical site more accurately.

In addition, here, the endoscopic surgery system has been described as an example, but the technology of the present invention can also be applied to, for example, a microscope surgery system.

＜12. Application example for moving objects＞ The technology of the present invention (the present invention) can be applied to various products. For example, the technology disclosed in the present invention can be implemented as being mounted on any type of mobile object such as automobiles, electric vehicles, hybrid vehicles, motorcycles, bicycles, personal mobility devices, aircraft, drones, ships, robots, etc. device.

FIG. 21 is a block diagram showing a schematic configuration example of a vehicle control system as an example of a mobile body control system to which the technology of the present invention can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG. 21 , the vehicle control system 12000 includes a drive system control unit 12010 , a vehicle body system control unit 12020 , an exterior information detection unit 12030 , an interior information detection unit 12040 , and an integrated control unit 12050 . In addition, as the functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio and video output unit 12052, and an in-vehicle network I/F (interface) 12053 are shown.

The drive system control unit 12010 follows various programs to control the actions of devices associated with the vehicle's drive system. For example, the drive system control unit 12010 serves as a driving force generating device for generating the driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering mechanism for adjusting the rudder angle of the vehicle. , and the control device of the braking device that generates the braking force of the vehicle.

The vehicle body system control unit 12020 follows various programs to control the operations of various devices equipped on the vehicle body. For example, the vehicle body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as headlights, taillights, brake lights, direction indicators, or fog lights. . In this case, the vehicle body system control unit 12020 may be input with radio waves emitted from the portable device that replaces the key or signals from various switches. The vehicle body system control unit 12020 accepts the input of such radio waves or signals and controls the door locking device, power window device, lights, etc. of the vehicle.

The vehicle exterior information detection unit 12030 detects information outside the vehicle on which the vehicle control system 12000 is mounted. For example, the camera unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture images of the exterior of the vehicle and receives the captured images. The off-vehicle information detection unit 12030 can perform object detection processing or distance detection processing of people, vehicles, obstacles, signs, or text on the road based on the received images.

The imaging unit 12031 is a photo sensor that receives light and outputs an electrical signal corresponding to the received amount of light. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. In addition, the light received by the imaging unit 12031 may be visible light or non-visible light such as infrared rays.

The in-vehicle information detection unit 12040 detects the information in the vehicle. The in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 that detects the driver's state, for example. The driver's state detection unit 12041 includes, for example, a camera that photographs the driver. The in-vehicle information detection unit 12040 can calculate the driver's fatigue or concentration based on the detection information input from the driver's state detection unit 12041, and can also determine the driver's level. Doze off or not.

The microcomputer 12051 can calculate the control target value of the driving force generating device, the steering mechanism or the braking device based on the information inside and outside the vehicle obtained by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and output a control command to the drive system control unit 12010 . For example, the microcomputer 12051 can implement ADAS (Advanced Driver Assistance System, advanced driving) including vehicle collision avoidance or impact mitigation, following driving based on vehicle distance, vehicle speed maintenance, vehicle collision warning, or vehicle lane departure warning, etc. The function of the auxiliary system is coordinated control for the purpose.

In addition, the microcomputer 12051 controls the driving force generating device, the steering mechanism, the braking device, etc. based on the information around the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, thereby making it possible to perform operations that do not depend on the driver. Coordinated control for the purpose of autonomous driving, etc. under the operation of the vehicle.

In addition, the microcomputer 12051 can output control instructions to the vehicle body system control unit 12020 based on the information outside the vehicle obtained by the vehicle outside information detection unit 12030. For example, the microcomputer 12051 controls the headlights in response to the position of the vehicle ahead or the oncoming vehicle detected by the vehicle exterior information detection unit 12030, and can perform coordinated control for the purpose of preventing glare, such as switching the high beam to the low beam. .

The sound and image output unit 12052 sends an output signal of at least one of sound and image to an output device capable of visually or audibly notifying information to passengers of the vehicle or outside the vehicle. In the example of FIG. 21 , an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are illustrated as output devices. The display portion 12062 may include, for example, at least one of an on-board display and a head-up display.

FIG. 22 is a diagram showing an example of the installation position of the imaging unit 12031.

In FIG. 22 , vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as imaging unit 12031.

The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front end protrusion of the vehicle 12100, the side mirrors, the rear bumper, the rear door, and the upper portion of the windshield in the vehicle compartment. The camera unit 12101 provided at the front end protrusion and the camera unit 12105 provided at the upper part of the windshield in the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided in the side view mirror mainly acquire side images of the vehicle 12100 . The camera unit 12104 provided in the rear bumper or the tailgate mainly acquires images of the rear of the vehicle 12100 . The images ahead obtained by the camera units 12101 and 12105 are mainly used for detection of vehicles or pedestrians ahead, obstacles, traffic lights, traffic signs or lanes, etc.

In addition, FIG. 22 shows an example of the imaging range of the imaging units 12101 to 12104. The imaging range 12111 shows the imaging range of the imaging part 12101 provided on the front protrusion. The imaging ranges 12112 and 12113 show the imaging ranges of the imaging parts 12102 and 12103 respectively installed on the side view mirror. The imaging range 12114 shows the imaging range provided on the rear bumper or the back. The camera range of the door camera unit 12104. For example, by overlapping the image data captured by the imaging units 12101 to 12104, a bird's-eye view of the vehicle 12100 from above can be obtained.

At least one of the camera units 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera including a plurality of imaging elements, or an imaging element having pixels for phase difference detection.

For example, the microcomputer 12051 obtains the distance to each three-dimensional object within the imaging range 12111 to 12114 and the temporal change of the distance (relative speed to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, In particular, from the nearest three-dimensional object located on the path in front of the vehicle 12100, a three-dimensional object traveling in approximately the same direction as the vehicle 12100 at a specific speed (for example, 0 km/h or more) can be extracted as the front vehicle. Furthermore, the microcomputer 12051 sets the vehicle distance that must be ensured in advance for the vehicle in front, and can perform automatic braking control (also including follow-stop control) or automatic acceleration control (also including follow-start control), etc. In this way, coordinated control can be carried out for the purpose of automatic driving, such as autonomous driving without relying on the driver's operation.

For example, the microcomputer 12051 can classify the three-dimensional object data related to the three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, telephone poles, and other three-dimensional objects based on the distance information obtained from the imaging units 12101 to 12104, and extract them. And used for automatic avoidance of obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines the collision risk indicating the risk of collision with each obstacle, and outputs an alarm to the driver through the audio speaker 12061 or the display unit 12062 when the collision risk is above a set value and a collision is possible. , or perform forced deceleration or avoidance steering through the drive system control unit 12010, so as to provide driving support for avoiding collisions.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can identify pedestrians by determining whether there are pedestrians in the captured images of the imaging units 12101 to 12104. Such identification of pedestrians is performed by, for example, a program that extracts feature points from the image taken by the imaging units 12101 to 12104 of the infrared camera, and performs pattern matching processing on a series of feature points showing the outline of the object to determine whether it is a pedestrian. conduct. When the microcomputer 12051 determines that there is a pedestrian in the image captured by the imaging units 12101 to 12104 and recognizes it as a pedestrian, the audio and image output unit 12052 controls the recognized pedestrian to overlap and display a square outline for emphasis. Display unit 12062. Furthermore, the audio image output unit 12052 may control the display unit 12062 so that an icon or the like showing pedestrians is displayed at a desired position.

As above, an example of the vehicle control system to which the technology of the present invention is applicable has been described. The technology of the present invention can be applied to the imaging unit 12031 and the like in the configuration described above. For example, the solid-state imaging device 1 shown in FIG. 1 can be applied to the imaging unit 12031. By applying the technology of the present invention to the imaging unit 12031, a captured image that is easier to observe can be obtained, thereby reducing driver fatigue.

＜＜13.Supplement＞＞ As mentioned above, the preferred embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, the technical scope of the present invention is not limited to the above-mentioned examples. As long as a person skilled in the art with general knowledge in the technical field of the present invention can obviously think of various variations or modifications within the scope of the technical ideas described in the scope of the patent application, it should be understood that these also belong to the technical aspects of the present invention. within the range.

In addition, the effects described in this specification are ultimately only illustrative or exemplary effects, and are not limiting effects. That is, the technology of the present invention can exert other effects in addition to the above-mentioned effects, and/or can exert other effects that are obvious to those skilled in the art based on the description of this specification, instead of the above-mentioned effects.

In addition, the following configurations also fall within the technical scope of the present invention. (1) A solid-state imaging element having: semiconductor substrate; a charge accumulation part, which is provided in the aforementioned semiconductor substrate and accumulates electric charge; A photoelectric conversion part is provided above the aforementioned semiconductor substrate and converts light into electric charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and At the end of the through-electrode on the side of the photoelectric conversion section, The cross-sectional area of a cross section of the conductor located at the center of the through-electrode that is perpendicular to the penetration direction of the through-electrode gradually increases toward the photoelectric conversion portion along the penetration direction. (2) The solid-state imaging element of (1) above, wherein the through-electrode is electrically connected to the photoelectric conversion portion and at least one or more pixel transistors provided in the semiconductor substrate. (3) The solid-state imaging element according to the above (1) or (2) further includes an insulating film covering the outer periphery of the conductor in front of the through-electrode. (4) The solid-state imaging element according to any one of the above (1) to (3), wherein the gradient of the outer peripheral surface of the conductor at the end on the side of the photoelectric conversion part is, It has an angle of not less than 1ﾟ and not more than 60ﾟ with respect to the central axis extending in the penetration direction of the conductor. (5) The solid-state imaging device according to any one of (1) to (3) above, wherein the conductor has a substantially cylindrical shape. (6) The solid-state imaging element according to the above (5), wherein a diameter of the conductor in the cross section on the side of the photoelectric conversion part is 1.2 times or more of a diameter of the conductor in the cross section on the charge accumulation part side. (7) The solid-state imaging element according to any one of the above (1) to (3), wherein in a cross-section when the through electrode is cut along the through direction, The end portion on the side of the photoelectric conversion portion of the conductor has two first branch portions branched from the central axis of the conductor. (8) The solid-state imaging element of (7) above, wherein the end portion of the conductor on the side of the photoelectric conversion portion further has a recessed portion located between the two first branch portions. (9) The solid-state imaging element of (7) or (8) above, wherein each of the first branch portions is curved in a circular arc drawn from the central axis. (10) The solid-state imaging element of (9) above, wherein each of the first branch portions is curved with a curvature radius of not less than 10 nm and not more than 1000 nm. (11) The solid-state imaging element according to the above (7), wherein in a cross-section when the through electrode is cut along the through direction, the end of the conductor on the side of the charge storage unit has two second points branched from the central axis. branch. (12) The solid-state imaging element of (11) above, wherein the first branch portions and the second branch portions are curved in an arc drawn from the central axis. (13) The solid-state imaging element of (12) above, wherein the radius of curvature of the first branch portion is greater than the radius of curvature of the second branch portion. (14) The solid-state imaging element according to any one of (1) to (13) above, wherein the end portion on the front side of the photoelectric conversion portion of the conductor is electrically connected to a wiring including a transparent conductor. (15) The solid-state imaging device according to any one of the above (1) to (14), wherein the photoelectric conversion part has: A common electrode shared by adjacent solid-state imaging elements; A readout electrode electrically connected to the aforementioned through-electrode; and A photoelectric conversion film is provided between the common electrode and the readout electrode and converts light into electric charge. (16) The solid-state imaging element of (15) above, wherein the photoelectric conversion film contains an organic material. (17) The solid-state imaging element of (15) or (16) above, wherein the photoelectric conversion portion further has an accumulation electrode facing the common electrode with the photoelectric conversion film and the insulating film interposed therebetween. (18) The solid-state imaging element according to any one of the above (1) to (17), further includes another photoelectric conversion portion disposed in the aforementioned semiconductor substrate for converting light into electric charges. (19) A solid-state imaging device having a plurality of solid-state imaging elements arranged in a matrix, and Each of the aforementioned solid-state imaging components has: semiconductor substrate; a charge accumulation part, which is provided in the aforementioned semiconductor substrate and accumulates electric charge; A photoelectric conversion part is provided above the aforementioned semiconductor substrate and converts light into electric charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and At the end of the through-electrode on the side of the photoelectric conversion section, The cross-sectional area of a cross section of the conductor located at the center of the through-electrode that is perpendicular to the penetration direction of the through-electrode gradually increases toward the photoelectric conversion portion along the penetration direction. (20) A method of manufacturing a solid-state imaging element, which manufactures a solid-state imaging element, and the solid-state imaging element has: semiconductor substrate; a charge accumulation part, which is provided in the aforementioned semiconductor substrate and accumulates electric charge; A photoelectric conversion part is provided above the aforementioned semiconductor substrate and converts light into electric charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and At the end of the through-electrode on the side of the photoelectric conversion section, The cross-sectional area of the cross section of the conductor located at the center of the through-electrode that is orthogonal to the penetration direction of the through-electrode gradually increases toward the photoelectric conversion portion along the penetration direction; and The aforementioned manufacturing methods include: Forming a through hole penetrating the aforementioned semiconductor substrate; Form an insulating film to cover the inner wall of the through hole; Etch the insulating film on the end portion of the through hole on the side of the photoelectric conversion portion; and The aforementioned through hole is embedded with a metal film.

1: Solid-state imaging device 10: Pixel array section 32: Vertical drive circuit section 34: Row signal processing circuit section 36: Horizontal drive circuit section 38: Output circuit section 40: Control circuit section 42: Pixel drive wiring 44: Vertical signal line 46 : Horizontal signal line 48: Input/output terminal 100: Solid-state imaging element (pixel) 100a: Solid-state imaging element 100b: Solid-state imaging element 200: Photoelectric conversion element 200a: Photoelectric conversion element 202: Upper electrode (common electrode) 204: Photoelectric conversion film 206: Lower electrode (readout electrode) 208: Storage electrode 300: Photoelectric conversion element 400: Photoelectric conversion element 500: Semiconductor substrate 502: Semiconductor region 510: Semiconductor region 512: Semiconductor region 514: Floating diffusion 516: Semiconductor region 520: Wiring layer 522: Wiring 524: Gate electrode/electrode 530: Interlayer insulating film 540: Insulating film 550: Fixed charge film 552: Insulating film 560: Insulating film 570: Metal wiring/wiring 580: High refractive index layer 582: Planarization Film 590: On-wafer lens 600: Through electrode 600a: Through electrode 600b: Through electrode 602: Conductor 602a: Conductor 602b: Branch portion (first branch portion) 602c: Conductor 602d: Branch portion (first branch portion) 604: Insulating film 606: Through hole 606a: Through hole 606b: Through hole 606c: Open end 610: Central axis 620: Recessed portion 650: Fixed charge film 800: Through electrode 802: Conductor 804: Insulating film 806: Through hole 808: Gap 900: Electronic machine 902: Camera device 910: Optical lens 912: Shutter mechanism 914: Driving circuit unit 916: Signal processing circuit unit 11000: Endoscopic surgery system 11100: Endoscope 11101: Lens barrel 11102: Camera head 11110: Surgical instrument 11111: Veress tube 11112: Energy treatment device 11120: Support arm device 11131: Operator/doctor 11132: Patient 11133: Hospital bed 11200: Trolley 11201: Camera control unit/CCU 11202: Display device 11203: Light source device 11204: Input Device 11205: Treatment tool control device 11206: Veress device 11207: Recorder 11208: Printer 11400: Transmission cable 11401: Lens unit 11402: Camera unit 11403: Drive unit 11404: Communication unit 11405: Camera head control unit 11411: Communication Department 11412: Image Processing Department 11413: Control Department 12000: Vehicle Control System 12001: Communication Network 12010: Drive System Control Unit 12020: Vehicle Body System Control Unit 12030: Vehicle External Information Detection Unit 12031: Camera Department 12040: Vehicle Information Detection Unit 12041: Driver status detection unit 12050: Integrated control unit 12051: Microcomputer 12052: Audio and image output unit 12053: Vehicle network I/F 12061: Audio speaker 12062: Display unit 12063: Instrument panel 12100: Vehicle 12101: Camera unit 12102: Camera unit 12103: Camera unit 12104: Camera unit 12105: Camera unit 12111: Camera range 12112: Camera range 12113: Camera range 12114: Camera range AA´: Line BB´: Line D1: Diameter D2: Diameter FD1: Node L : Distance RST1: Reset signal line RST2: Reset line SEL1: Selection line SEL2: Selection line TG2: Transmission gate line TR1 _amp : Amplification transistor TR1 _rst : Reset transistor TR1 _sel : Selection transistor TR2 _amp : Amplification Transistor TR2 _rst : reset transistor TR2 _sel : selection transistor TR2 _trs : transmission transistor V _DD : power circuit V _OU : selection line VSL1: signal line VSL2: signal line

FIG. 1 is a schematic plan view of a solid-state imaging device 1 according to an embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of the PD 200 included in the solid-state imaging device 100 according to the embodiment of the present invention. FIG. 3 is an equivalent circuit diagram of the PD 300 included in the solid-state imaging device 100 according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the solid-state imaging device 100 according to the embodiment of the present invention. FIG. 5 is an explanatory diagram for explaining the process of creating the embodiment of the present invention. FIG. 6 is a partially enlarged cross-sectional view of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view of the through-electrode 600 taken along line A-A′ and line B-B′ in FIG. 6 . FIG. 8 is a schematic diagram of the upper part of the through-electrode 600 according to the first embodiment of the present invention. FIG. 9 is an explanatory diagram (Part 1) for explaining the manufacturing method of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 10 is an explanatory diagram (Part 2) for explaining the manufacturing method of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 11 is an explanatory diagram (Part 3) for explaining the manufacturing method of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 12 is an explanatory diagram (part 4) for explaining the manufacturing method of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 13 is an explanatory diagram (Part 5) for explaining the manufacturing method of the solid-state imaging element 100 according to the first embodiment of the present invention. FIG. 14 is a cross-sectional view of a solid-state imaging element 100a according to the second embodiment of the present invention. FIG. 15 is a schematic diagram of the upper part of the through-electrode 600a according to the second embodiment of the present invention. FIG. 16 is a schematic diagram of the upper part of the through-electrode 600b according to the third embodiment of the present invention. FIG. 17 is a cross-sectional view of a solid-state imaging element 100b according to the fourth embodiment of the present invention. FIG. 18 is an explanatory diagram showing an example of the electronic device 900 according to the fifth embodiment of the present invention. FIG. 19 is a diagram showing an example of the schematic configuration of the endoscopic surgery system. FIG. 20 is a block diagram showing an example of the functional configuration of the camera head and CCU. FIG. 21 is a block diagram showing an example of the schematic configuration of the vehicle control system. FIG. 22 is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection unit and the camera unit.

100: Solid-state imaging element (pixels)

200: Photoelectric conversion element

202: Upper electrode (common electrode)

204: Photoelectric conversion film

206: Lower electrode (readout electrode)

300: Photoelectric conversion element

400: Photoelectric conversion element

500:Semiconductor substrate

502: Semiconductor area

510: Semiconductor area

512:Semiconductor area

514: Floating diffusion part

516:Semiconductor area

520: Wiring layer

522:Wiring

524: Gate electrode/electrode

530: Interlayer insulation film

540:Insulating film

550: Fixed charge film

552:Insulating film

560:Insulating film

570:Metal wiring/wiring

580: High refractive index layer

582:Planarizing film

590: Lens on chip

600:Through electrode

602: Electrical conductor

604:Insulating film

650: Fixed charge film

Claims (18)

A solid-state imaging element including: a semiconductor substrate; a charge storage unit that is provided in the semiconductor substrate and accumulates charges; a photoelectric conversion unit that is provided above the semiconductor substrate and converts light into charges; and a through-electrode , which penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and at the end of the through electrode on the side of the photoelectric conversion part, there is a gap between the conductor located at the center of the through electrode and the through electrode The cross-sectional area of a cross section orthogonal to the penetration direction gradually increases along the penetration direction toward the photoelectric conversion portion; wherein in the cross section when the penetration electrode is cut along the penetration direction, the end of the conductor on the side of the photoelectric conversion portion The first branch portion has two first branch portions branched from the central axis of the conductor, and each of the first branch portions is curved to form an arc from the central axis. The solid-state imaging element according to claim 1, wherein the through-electrode is electrically connected to the photoelectric conversion portion and at least one or more pixel transistors provided in the semiconductor substrate. The solid-state imaging element according to claim 1 further includes an insulating film covering the outer periphery of the conductor in front of the through-electrode. The solid-state imaging element according to claim 1, wherein the gradient of the outer peripheral surface of the conductor at the end on the side of the photoelectric conversion part is 1° or more and 60° with respect to a central axis extending in the penetration direction of the conductor. The following angle. The solid-state imaging device of claim 1, wherein the conductor has a substantially cylindrical shape. The solid-state imaging element according to claim 5, wherein a diameter of the conductor in the cross section on the side of the photoelectric conversion part is 1.2 times or more of a diameter of the conductor in the cross section on the charge accumulation part side. The solid-state imaging element according to claim 1, wherein the end portion of the conductor on the side of the photoelectric conversion portion further has a recessed portion located between the two first branch portions. The solid-state imaging element according to claim 1, wherein each of the first branch portions is curved with a radius of curvature of not less than 10 nm and not more than 1000 nm. The solid-state imaging element according to claim 1, wherein in a cross-section when the through electrode is cut along the through direction, an end portion of the conductor on the side of the charge storage portion has two second branch portions branched from the central axis. . The solid-state imaging element of claim 9, wherein each of the aforementioned first branch portions and each of the aforementioned second branches The portion is curved in an arc drawn from the aforementioned central axis. The solid-state imaging element of claim 10, wherein the curvature radius of the first branch portion is greater than the curvature radius of the second branch portion. The solid-state imaging element according to claim 1, wherein the end portion of the conductor on the side of the photoelectric conversion portion is electrically connected to a wiring including a transparent conductor. The solid-state imaging element of claim 1, wherein the photoelectric conversion portion has: a common electrode shared by adjacent solid-state imaging elements; a readout electrode electrically connected to the through-electrode; and a photoelectric conversion film It is disposed between the common electrode and the readout electrode and converts light into electric charges. The solid-state imaging device according to claim 13, wherein the photoelectric conversion film contains an organic material. The solid-state imaging element according to claim 13, wherein the photoelectric conversion portion further has an accumulation electrode facing the common electrode with the photoelectric conversion film and the insulating film interposed therebetween. The solid-state imaging element of Claim 1 further includes another photoelectric conversion portion disposed in the semiconductor substrate and converting light into electric charge. A solid-state imaging device having a plurality of solid-state imaging elements according to any one of claims 1 to 16 arranged in a matrix. A method of manufacturing a solid-state imaging element, which is a method of manufacturing a solid-state imaging element, the solid-state imaging element having: a semiconductor substrate; a charge accumulation portion provided in the semiconductor substrate and accumulating charges; and a photoelectric conversion portion provided in the semiconductor above the substrate, and converts light into charges; and a through-electrode that penetrates the semiconductor substrate and electrically connects the charge storage part and the photoelectric conversion part; and at the end of the through-electrode on the side of the photoelectric conversion part, The cross-sectional area of the cross section of the conductor located at the center of the through-electrode that is perpendicular to the penetration direction of the through-electrode gradually increases along the penetration direction toward the photoelectric conversion portion; where the cross-section when the through-electrode is cut along the penetration direction In the method, the end portion on the side of the photoelectric conversion portion of the conductor has two first branch portions branched from the central axis of the conductor; and the manufacturing method includes: forming a through hole penetrating the semiconductor substrate; and covering the conductor. forming an insulating film on the inner wall of the through hole; etching the insulating film at the end of the through hole on the side of the photoelectric conversion portion; and burying the through hole with a metal film so that each of the first branch portions Bend in an arc drawn from the aforementioned central axis.